| .污染土壤不同粒级团聚体中铅的富集特征及其与叶类蔬菜铅吸收之间的相关性[J].农业环境科学学报,2013,32(3):. |
| 污染土壤不同粒级团聚体中铅的富集特征及其与叶类蔬菜铅吸收之间的相关性 |
| A Correlation Between Enrichment Characteristics of Lead in Different Particle-size Fractions of Soil Aggregates and Lead Concentrations of Leafy Vegetables |
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| DOI：10.11654/jaes.2013.03.022 |
| 中文关键词: 土壤团聚体 铅 叶菜 分布 吸收 相关性 |
| 英文关键词: soil aggregates lead leafy vegetables distribution adsorption correlation |
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| 摘要点击次数: 2031 |
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| 中文摘要: |
| 研究土壤重金属团聚体颗粒组微域环境的空间分异，对阐明土壤重金属环境行为具有重要意义，目前对于铅（Pb）在土壤不同粒级团聚体组分中分布及其与蔬菜吸收相关性方面的研究仍然比较缺乏。选取22种典型土壤，采用盆栽试验通过人工添加硝酸铅的方法，测定分析了这些土壤不同粒级团聚体组分中Pb含量及其与两种叶菜（苋菜和空心菜）Pb吸收之间的相关性。结果表明粒径大小对于Pb在土壤中分布有显著影响：各粒级Pb含量为71.3~2245.4 mg·kg-1，根据各粒级组分分布，可计算出2~0.5 mm粒级Pb含量占全量的比例为1.21%~28.96%，0.5~0.25 mm粒级Pb所占比例为1.98%~22.15%，0.25~0.05 mm粒级Pb所占比例为3.29%~38.41%，0.05~0.002 mm粒级Pb所占比例为4.94%~68.17%，<0.002 mm粒级Pb所占比例为2.30%~56.50%。Pb在红壤等14种土壤不同粒级团聚体中分布随着粒径减少大致呈递增趋势，黏粒组的团聚体普遍呈现出Pb富集现象；在潮土等8种土壤中，Pb在不同粒级团聚体中分布呈现双峰分布趋势，在黏粒组和粗砂组团聚体中都出现富集现象。此外，pH、有机质、阳离子交换量和活性氧化铁等对不同粒级团聚体中Pb的富集系数有显著作用。粉粒组团聚体中Pb含量与叶菜类蔬菜Pb的吸收呈显著相关。 |
| 英文摘要: |
| This work was conducted to investigate the characteristics of lead（Pb） in different particle-size fractions of soil aggregates. Soil samples with a range of chemical and physical properties were collected from 22 rural regions of China. Pb in soil aggregates from different particle-size fractions were compared with the its contents in edible amaranth（Amaranthus mangostanus L.） and water spinach（Ipomoea aquatica Forsk） grown on soils in a pot experiment study. Soil aggregates were partitioned into five particle-size fractions：coarse sand（2~0.5 mm）, medium sand（0.5~0.125 mm）, fine sand（0.125~0.05 mm）, silt（0.05~0.002 mm） and clay（<0.002 mm）. It was clear that Pb were not homogeneously distributed over the various particle-size fractions, suggesting that particle size exercises a determining influence on the partitioning of heavy metals. Concentrations of Pb in different fractions ranged from 71.3~2245.4 mg·kg-1. According to particle distribution of the tested soil samples, it can be calculated that concentration proportions of Pb in different particle fractions were 1.98%~22.15% in 2~0.5 mm fraction, 1.98%~22.15% in 0.5~0.25 mm fraction, 3.29%~38.41% in 0.25~0.05 mm fraction, 4.94%~68.17% in 0.05~0.002 mm fraction and 2.30%~56.50% in <0.002 mm fraction. Generally in 14 soils, Pb tended to enriched into finer particle-size fractions, resulting in the most metals accumulate in the clay. In other 8 soils, Pb had bimodal distributions across the particle-size fractions, i.e. the metals tended to accumulate in the clay and one sand fraction of the soils. Correlation analysis showed that pH, organic matter, CEC and amorphous Fe oxides had significant influence on the enrichment index of Pb in different particle-size fractions, and soil aggregates with silt size were found to be the major fraction responsible for Pb adsorption in leafy vegetables. From the soil textural data, it was possible to infer the relative importance of the fractions with respect to their contribution to metal availability. |
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